Typewriting machine



Au 8, 1939. w, A, DQBSON I 2,168,516

TYPEWRITING MACHINE Filed March 18, 1936 Patented Aug. 8, 1939 UNITED STA'iEfi LQA'EENT QFFEQE to Underwood Elliott Fisher Company,

New

York, N. Y., a corporation of Delaware Application March 18, 1936, Serial No. 69,537

18 Glaims.

This invention relates to typewriters and more particularly to devices for adjusting the reaction of key-levers for variations in. finger-pressure of different operators. Operators vary in the degree of lightness or heaviness of touch, and in manifolding employ a difierent touch than is the case with the usual typewriting. To meet the several conditions of use, it is desirable to provide a construction having strong, simple and precise parts, a quick and facile manual adjustment of the key-lever yieldability for several conditions, accessible at a convenient point outside the typewriter, and an indicator that shows the operator the exact adjustment.

A feature of the invention. is the provision of a universal bar and a spring for returning the bar to normalcy after depression by a key-lever, coupled with a second adjustable spring which becomes effective for co-operative action with the first spring after a predetermined depression of a key-lever, whereby the keys may be adjusted for operators of very light touch and for operators with a heavier touch.

Another feature of the invention is the provision of a simple, low-cost, durable, and serviceable construction for the purpose of permitting the adjustment of the resilient yieldability of the keys to the differing touch of various operators that may be installed in an Underwood portable typewriter of present structure with few and simple manufacturing adjustments.

Another feature of the invention is the provision of a manual device for adjusting the keytouch to several conditions accessible exteriorly of the typewriter, and the provision of an index and scale visible exteriorly of the typewriter indicating each of the several adjustments.

Another feature of the invention is the provision of a second spring connected with the universal bar which has a lost-motion connection, whereby it becomes effective only after the universal bar has been depressed an amount equal to the lost motion. This construction permits of an adjustment for avery light touch. To prevent torsion or skewing on the universal bar two springs may be provided, one on each end, each having the same tension and the same lost-motion connection. The rigidity of the universal bar and its resistance to bending, as well as keeping the bar relatively light and small, are essential to compact and low-cost manufacture. Any bending or yielding of the universal bar may easily affect the accuracy of operation. of the ribbon-vibrating mechanism, or of the escapement. The provision of arms slidably mounted, in

brackets, in the same direction as the paths of expansion and contraction of the springs, eliminates the need for extra space, and results in a compact construction easily positioned 'within present existing vacancies between parts in an -5 Underwood portable typewriter. The provision of a transverse rotatable shaft permits of the mounting of eccentric cams on the shaft, one

beneath each of the slidable arms, whereby the rotation of the shaft raises and lowers the arms .10 equally and simultaneously, and so therefore increases and decreases the tension of the secondary pair of springs equally and uniformly to concomitantly vary the yieldable resistance of the universal bar and consequentlythe yieldablh 5 ity of the keys, which permits key-adjustment for varying touch and also permits adjustment for manifolding. The index shows any selected adjustment, and there is provided further a yieldable stop which holds the shaft at any rotational 20 adjustment selected.

Another feature of the invention is the provision of a simple, low-cost construction whereby the key-touch may. by rendered more agreeable and the operation of the machine less fatiguing to the operator, and also whereby the action of the keys may be varied from exceedingly stiff and resisting to very elastic.

Other features and advantages will hereinafter appear.

In the accompanying drawing,

Figure 1 is a perspective View with parts broken away and parts in section.

Figure 2 is a side elevation partly in section and with parts broken away, also showing a lever con- .35 nection for operating the ribbon-feed mechanism.

Figure 3 is a fragmentary elevation, partly in section, of a key-lever overlying the edge of a universal bar, and spring suspension of the universal bar on an adjustable arm.

Figure 4 is a fragmentary sectional elevation, partly in section, showing the left end of the adjustment-control rod and allied parts.

Figure 5 is an elevation of the dial.

Figure 6 is a view similar to that of Figure 3, but showing a modification.

Certain parts of an Underwood portable typewriter which intimately co-operate with the im provements disclosed herein are shown in the 60 drawing, comprising a frame 1 covered by a mask 8, and key-levers 9. having recesses NJ on the upper surfaces at the rear ends pivoted on the lower edge of depending cross-flange H. A lock-plate I2 is fastenedto the flange H and locks the key- 55 levers 9 against displacement. A cross-piece |3 in the frame supports a row of upwardly-projecting screws 4 which carry at their upper ends cylindrical pins l5. Mounted on each pin is a coil-spring l6 which is held under each key-lever 9 by a pointed downward projection l1. These tension-springs l6 tend to hold the key-levers 9 in the upper or normal position. The lower ends of the screws M are each provided with two opposed flat faces la, the rear face being engaged and locked yieldably against turning by the edge of a loopspring I9, which is held by screws 29, or other suitable means on the under surface of the cross-piece 3.

A link-arm 24 is pivoted on a cross-rod 25 and has a pin-and-slot connection 26 with the key lever 9. A link 21 is pivoted on the rear end of the link-arm 24, and is also pivoted to the b0ttom of a type-bar 28, type-bar 28 being pivoted on a type-bar rod 29.

A universal escapement-bar 30 ure 2 in the inoperative 28. Each type-bar 28 is provided with type 3|. In the inoperative position each type-bar 28 reclines on a stop 32, and the upward movement of the key-levers 9 is checked by a stop 33. A platen 34 is indicated in Figure 1.

A universal bar 35 having side arms 36 is pivotally mounted for upward and downward movement on a cross-rod 31, which also acts as a rock-shaft, and is mounted at the opposite ends in brackets 38 suitably fastened to a depending flange of the cross-piece l3.

Referring to Figure 2, an arm 39 is fast on the cross-rod 31, and has a pivotal connection 40 with the rear end of a horizontal arm 4|, which carries at the forward end a tooth 42 which resiliently engages a ribbon ratchet-wheel 43 mounted on a ribbon-shaft 22. The backward turning of the ribbon ratchet-wheel 43 is prevented by a pawl 44 which oscillates on a pin 2|, the rear extension of the pawl 44 being tied to the forward part of the arm 42 by means of a spring 45. 7

A bracket 45 centrally mounted on the crossplece' l3 supports at its forward end a tensionspring 41, which is pinned centrally on the upper side of the universal bar 35. A pair of similar coil-springs 48 are fastened at their lower ends near the universal bar but on the side arms 36, each coil-spring terminating at its upper end in a loop 49, which lies within but above the bottom of a V-slot 59, which may also be designated as a lost-motion slot formed on the upper side of a rearwardly-extending arm 23 supported by an inclined slide 5|, which is mounted slidably in slotted arms 52 in a bracket 53, which is secured by rivets 54 on the inside wall of the frame 1. It will be understood that there is a coil or tension spring 48 on or near each end of the universal bar 35 supported by these lost-motion slots provided in the arms 5| which are slidably mounted in the brackets 53 on the frame, the parts being symmetrical. Two eccentric cams 55 are mounted on a shaft 56 which is journaled in the frame of the machine, one cam being mounted near each end of the shaft 56, and the cams being symmetrically positioned. A set-screw 51, shown in Figure 3, looks each cam 55 in its fixed position on the shaft 56. A stop 58 on each cam 55 limits the movement of pointer 5| to the right of numeral I. These cams 55 engage the lower ends of the inclined slides 5| and form stops or rests for the slides to hold them against their downward movement.

is shown in Figposition of a type-bar A knurled thumb-piece 59 or manipulative means is mounted on a left extremity of the shaft 55 outside the frame I and the mask 8, and is locked against rotation on the shaft 55 by a set-screw 60 positioned between the frame 1 and the mask 8, as shown in Figure 4. Mounted on the knurl 59 is the pointer 6|, which indicates the index numerals I, 2, 3, 5, 5 and 6, according to the rotary position of the shaft 56. The pointer BI is near the index numeral I, as shown in Figure 5, which is also the position of the cams 55 and the slide-arms 5|, or, in other words, the initial position of the tension-springs 48, as shown in Figures 1, 3 and 6. The neck oi the knurl 59 is provided with horizontal grooves 63 which are engaged by a horizontal ridge 64 which is formed in the lower end of a flat spring 55, which is fastened in the space between the frame "I and the mask 8 by set-screws 66 on the outer wall of the frame I. A stop 3'! is set in the outer wall of the frame 1 near the horizontal grooves 53 in a position to engage the set-screw 60, thereby providing a stop against the turning of the knurl 59 beyond the position of final adjustment at which the pointer 6| would be opposite the numeral 5 shown in Figure 5.

Referring to Figure 3, there are shown above the cam 55 dotted lines 68, 69, 79, 1| and 72 which indicate the positions of the bottom of the slides 5|, when the index pointer 6| is set respectively by the numerals 2, 3, 4, 5 and 5. Reference is made to Figure 6 for a modification in which two supplemental V-slots are provided on the arm 23, one shorter V-slot 13 on the right of the V-slot 50 as shown, and a V-slot 14' at the left of the V-slot 59 as shown. A tie-rod 75 connects the rear bottom extremities of the frame 7.

In Figure 3 it will be noted that the height of the loop 49 over the bottom of the groove 59, or the downward motion of the spring 48, or its lost motion, is only a fraction of the total downward movement of the universal bar 35, or the distance between the full-line position and the dotted-line position of the universal bar. Throughout the initial part of the down stroke of the universal bar 35, or the part of the down stroke that is equivalent to the distance that the loop 49 is initially above the bottom of the V- slot 50, the only tension that is effective on the universal bar is that of the centrally positioned light coil-spring 41. During the last part of the down stroke of the universal bar 35, the pair of coil-springs 48 are efiective, continuously increasing their tension up to the point that the down stroke of the key-lever 9 culminates in the contact of the type 3| with the platen 34. Instantly upon removing the finger from the keylever 9, the three springs 4'! and 48, 43 are effective under their greatest tension to lift the key-levers 9 and to return the type-bar 28 to the segmental rest 32, the two springs 48, 48 being equally and uniformly effective on the extremities of the universal bar 35, and the coilspring 41 being centrally effective, whereby uniform upward tension is exerted on the universal bar 35. The Figure 3 position is that of the Figure 5 position in which pointer 5| is at index numeral Let it be assumed that the knob 59 is turned from index numeral to index numeral 2, and that simultaneously the cams 55 are rotated to the left, thereby lifting the slides 5| a distance that is equal to the difference between the top of the cams 55 and the horizontal line 58, where iii ,inauguration of the down stroke of a. key-lever forthwith, all three coil-springs 41, 48, 48 exert upward tension on the universal bar 35, and the tension at the end of the down stroke is greater than in the case of the setting shown in Figures 3 and 5.

Similarly the tension is increased by turning the index pointer' iii to the numeral 3, at which setting the bottom of the slides 5| is at the line 69 in Figure 3, and so index numerals i, 5 and 6 correspond respectively to bottom positions of the slides 5! at lines in, H and H2.

The modification shown in Figure 6 provides two additional lost motion V-slots, V-slot 73 of less depth than V-slot 5! and at the right thereof, whichmay be used for the original setting of the loop 49 where slightly more initial tension is :desired, and V-slot 14 of somewhat greater depth permitting more lost motion to the pair of springs lt, thereby providing for the condition of a lighter touch than that shown in Figure 3. In the case of an initial setting in V-slot it, it will be understood the five other settings indicated -by index numerals, 2, 3, 4, 5 and 6 will be proportionally of greater tension, each setting than the corresponding setting in the construction shown in Figure 3, and likewise in the case of an initial setting in V-slot It the five other settings will be of proportionally less ten men.

It will be further understood that the degree of variation in the tensions procured at the vari ous settings may be decreased by increasing the number of teeth 63 that intercept the horizontal ridge 54' onthe lock-spring 65, or by any other desired construction known in the art. Such modifications are not shown.

Variations may be resorted to within the scope of the invention, and portions. of the improvements may be used without others.

Having thus described my invention, I claim: 1.. A typewriter comprising, in combination,

key-levers, a universal bar extending across and beneath said key-levers and depressible by said key-levers, a springcentrally connected with said bar and operable to resist the depression of said bar and to return the bar to normalcy, a pair springs which become efiective simultaneously, whereby skewing or warping of the universal bar is prevented, after a. predetermined movement of depression of a key-lever, and means for slmultaneously adjusting said of springs to vary their tension.

2. A typewriter comprising, in combination, key-levers, a universal bar extending across and beneath said key-levers and depressible by said keydevers, a spring centrally connected with said bar and operable to resist the depression of said bar and to return the bar to normalcy, a pair of springs which become eliective simultaneously, whereby skewing or warping of the universal bar is prevented, after a predetermined movement of depression of a key-lever, means for simultaneously adjusting said pair of springs to vary their tension, and an index for indicating the adjustment of said pair of springs.

3. A typewriter comprising, in combination, key-levers, a universal bar extending across and beneath said key-levers and depressible by said key-levers, a spring connected with said bar and operable to resist the depression of said bar and to return the bar to normalcy, a second spring which becomes effective for co-operative action with the first spring after a predetermined move ment of depression of a key-lever, an arm having a lost-motion support for said second spring, and means for moving said arm to adjust the tension of said second spring.

4. A typewriter comprising, in combination, key-levers, a universal bar extending across and beneath said key-levers and depressible by said key-levers, a spring connected with said bar and operable to resist the depression of said bar and to return the bar to normalcy, a pair of springs, one fastened on each end of the universal bar,

which become efiective simultaneously, whereby skewing or warping of the universal bar is prevented, aiter a. predetermined movement of depression of a key-lever, and means for simultaneously adjusting said pair of springs to vary their tension.

5. -A typewriter comprising, in combination, key-levers, .a universal bar extending across and beneath said keylevers and depressible by said key-levers, a spring connected with said bar and operable to resist the depression of said bar and to return the bar to normalcy, a second spring which becomes effective for co-operative action with the first spring after a predetermined movement of depression of a key-lever, an. arm having a lost-motion support for said second spring, and means, comprising a cam, for moving said arm to adjust the tension of said second spring.

6. A typewriter comp-rising, in combination, key-levers, a universal bar extending across and beneath said key-levers and depressible by said key-levers, a spring connected with said bar and operable to resist the depression or" said bar and to return the bar to normalcy, a second spring which becomes eficctive for (to-operative action. with the first spring after a predetermined movement of depression of a key-lever, an arm for supporting said second spring, a lost-niotion engagement between said arm. and said second spring, and means for moving said arm to adjust the tension of said second spring.

'7. A typewriter comp-rising, in combination, key-levers, a universal bar extending across and beneath said key-levers and depressible by said key-levers, a main spring connected with said bar and operable to resist the depression of said bar and to tend to return the bar to normalcy, a pair of returning springs auxiliary to said main spring, one fastened to each end of the universal bar, a movable arm for supporting each auxiliary spring, a shaft rotatably mounted and supporting cams, one near each arm, manuallyoperable means connected with said shaft and accessible from outside the typewriter for turn ing said cams to adjust said pair of auxiliary springs, an indicator mounted on said shaft, and yieldable means for holding said cams in a pin-- rality of positions rotatably.

8. A typewriter comprising, in combination, key-levers, a universal bar extending across and beneath said key-levers and depressible by said key-levers, a main spring connected with said bar and operable to resist the depression of said bar and tending to return the bar to normalcy, an auxiliary spring fastened at one end of the universal bar, a movable arm for supporting said auxiliaryspring, a shaft rotatably mounted and supporting a cam which engages said movable arm, manually-operable means connected with said shaft and accessible from outside the type-writer for turning said cam to adjust said auxiliary spring, an indicator for indicating the position of said cam, and yieldable means for holding the cam in a plurality of rotative adjustments.

9. A typewriter comprising, in combination, key-levers, a universal bar extending across and beneath said key-levers and depressible by said key-levers, a spring connected with said bar and operable to resist the depression of said bar and to return the bar to normalcy, an auxiliary spring fastened at one end of the universal bar, a movable arm for supporting said auxiliary spring, a bracket for slidably supporting said arm, a shaft rotatably mounted and supporting a cam which engages said movable arm, manually-operable means connected with said shaft and accessible from outside the typewriter for turning said cam to adjust said auxiliary spring, an indicator for indicating the position of said cam, and yieldable means for holding the cam in a plurality of rotative adjustments.

10. A typewriter comprising, in combination, key-levers, a universal bar extending across and beneath said key-levers and depressible by said keylevers, a spring connected with said bar and operable to resist the depression of said bar and tending to return the bar to normalcy, an auxiliary spring fastened at one end of the universal bar, a movable arm for supporting said auxiliary spring, a bracket for slidably supporting said arm, a shaft rotatably mounted and supporting a cam which engages an end of said movable arm, manually-operable means connected with said shaft and accessible from outside the typewriter for turning said cam to adjust said auxiliary spring, an indicator for indicating the position of said cam, and yieldable means for holding the cam in a plurality of rotative adjustments.

11. A typewriter comprising, in combination, key-levers, a universal bar extending across and beneath said key-levers, a main spring centrally connected with said universal bar and operable to resist the depression of said bar and tending to return the bar to normalcy, a pair of auxiliary springs, one fastened at each end of the universal bar, movable arms for supporting said auxiliary springs, brackets for slidably supporting said arms, a shaft rotatably mounted and supporting cams which engage the ends of said movable arms, manually-operable means connected with said shaft and accessible from outside the typewriter for turning said cams to adjust said pair of auxiliary springs simultaneously, an index to show the adjustment of said pair of auxiliary springs, and a plurality of radially disposed stops on said shaft, and resilient means engageable with said stops whereby the tension of said pair of auxiliary springs is yieldably maintained many adjusted position.

12. A typewriter comprising, in combination, key-levers, a universal bar extending across and beneath said key-levers, a main spring centrally connected with said universal bar and operable to resist the depression of said bar and to return the bar to normalcy, a pair of auxiliary springs, one fastened at each end of the universal bar, movable arms for supporting said auxiliary springs, brackets for slidably supporting said arms, a shaft rotatably mounted and supporting cams which engage the ends of said movable arms, manually-operable means connected with said shaft and accessible from outside the typewriter for turning said cams to adjust said pair of auxiliary springs simultaneously, an index to show the adjustment of said pair of auxiliary springs, a plurality of radiallydisposed and horizontally-grooved stops on said shaft, and a stop spring having a ridge engageable with said stops, whereby the tension of said pair of auxiliary springs is yieldably maintained in any adjusted position.

13. In a typewriter having a system of keylevers, in combination, a universal bar mounted for actuation by each of the key-levers, a spring connected to said bar to yieldably resist movement thereof by the key-levers, a pair of auxiliary springs connected to said bar to co-operate with the first spring in yieldably resisting the movement of said bar, a separate movable mount for each auxiliary spring, and manually settable means for moving said mounts so as to adjust the tension of each auxiliary spring simultaneously.

14. A typewriter comprising, in combination. key-levers, a universal bar extending across and beneath said key-levers and depressible by said key-levers, a spring connected to said bar and operable to resist the depression of said bar and to return the bar to normalcy, a second spring connected to said bar and which becomes effective for co-operative action with the first spring after a predetermined movement of depression of a key lever, an arm for supporting said second spring, and a rotatable camv for moving said arm whereby to adjust the tension of said second spring.

' 15. A typewriter comprising, in combination, key-levers, a universal bar extending across and beneath said key-levers and depressible by said key-levers, a spring connected to said bar and operable to resist the depression of said bar and to return the bar to normalcy, a second spring connected to said bar, which becomes effective for cooperative action with the first spring after a predetermined movement of depression of a key-lever, an arm for supporting said second spring, means for moving said arm, comprising a rotatable cam, to adjust the tension of said second spring, and means for holding the cam in the various positions of adjustment.

16. A typewriter comprising, in combination, key-levers, a universal bar extending across and beneath said key-levers and depressible by said keylevers, a spring connected to said bar and operable to resist the depression of said bar and to return the bar to normalcy, a second spring connected to said bar, which becomes effective for co-operative action with the first spring after a predetermined movement of depression of a key-lever, an arm. for supporting said second spring, means for moving said arm, comprising a rotatable cam, to adjust the tension of said second spring, and yieldable means for holding the cam in various positions of adjustment.

17. A typewriter comprising, in combination, key actuated type actions, a universal bar movable by any of said type actions, a spring connected to said bar and effective at the operation of any of said type actions to resist the movement of said bar and to return the bar to normalcy together with any one of said type actions, an auxiliary spring having connection at one end to said bar, a support having connection to the other end of said auxiliary spring, one of said connections being adapted to permit an initial limited motion of said bar without resistance of said auxiliary spring, whereby the latter is adapted to cooperate with the first spring after a predetermined movement of depression of any type action key, and means for adjusting said auxiliary-spring support for adjusting said limited motion of said bar to vary the point in the depression of said bar at which said auxiliary spring becomes effective.

18. A typewriter comprising, in combination, a casing, key actuated type actions, a key-touch controlling universal bar movable by said type actions, a spring connected to said bar and effective at the operation of any of said type actions to resist the movement of said bar and to return said bar to normalcy together with any one of said type actions, an auxiliary spring having connection at one end to said bar, shiftable means having connection to the other end of said auxiliary spring, one of said connection being adapted to permit initial limited motion of said bar Without resistance of said auxiliary spring, and manipulative means on the outside of the casing, adapted to adjust said shiftable means to different positions for reducing said limited motion and successively adjusting the tension of said auxiliary spring to enable it to vary the 10 resistance of all of the type action keys uniformly.

WILLIAM A. DOBSON. 

